OK... i've got a question. Were there any differences in the TPI and trans in the 85 irocs and z28's.

The reason i'm asking.. 3 or 4 years ago I came across an 85 iroc that had been sitting for the last 20 years. The guy that owned it got rear ended back in 86, had the dealership fix it, and then went ballistic when they gave him the bill. Years of fighting went on and it ended up just sitting there until they got the paperwork to sell it for parts just to get it out from behind the building.

I put the engine/trans and just about everything else from it in my car because i was about to need a trans.. and figured since i had a low mile engine.. why not just put them both in? It is WAY more powerful than what was in it. My original tpi had great compression, great power, upgraded cam that really bumped it up.. and it was absolutely no comparison to this new one.

Some strange things on the iroc parts car... it had no dash vents, no a/c. I've never seen one without dash vents.. did they even make them like that? The seats didn't have that repeating iroc pattern either, they're just solid black.

Might be a stupid question, just wanted to ask and see.

 

. Here's some info that might be useful:

https://www.thirdgen.org/tech-data

A/C delete.

JamesC

 

There are "stories" of cars (mainly 85s) with TPI engines that end up being MUCH stronger than advertised, and more powerful than the 350 that came out two years later. I have a friend that had an 85 TPI T/A that ran mid 13s with an airfoil and a shift-kit, and that's it. I also saw timeslips years ago at the T/A nationals of a bone-stock TPI 305 that ran 14 flat.

I have no other information other than these examples, so take it with a grain of salt. But it sounds like you got one of these "superbeast" 305s.

 

....Were there any differences in the TPI and trans in the 85 irocs and z28's.

Historically speaking, no difference. Keep in mind that from 1985 thru 1987, the IROC-Z was only a handling and appearance package on the Z28. The drivetrain was identical with one exception, the 350 (L98) was an option only on the 1987 Z28 with the IROC-Z option. Just look here:

https://www.thirdgen.org/forums/hist...e-options.html

 

there may be a difference in performance in 85 between irocs and z28's

because some irocs got the G92 option / 3.42 gears

but the z28 got only 3.23 gears

 

My friend said basically the same thing. He called them fluke engines. Everything on them is the same, just for some reason things work better than expected.

I guess all the parts just came together perfectly and made it what it is.

 

there are fluke engines in almost every thing gm has ever made, i.e. my buddy had a 98 ls1 car and it ran hi 12's stock with only a flowmaster..... his l2000 ran mid to hi 14's set up the same way. both cars were optioned the same way only difference was year and color.